Impact of caffeine at the A2A receptors of olfactory bulb, brainstem and striatum of rotenone rat model of Parkinson disease.

Abstract

Parkinson disease is a complex neurodegenerative disease and presently the fastest growing neurological disorder globally, yet there has not been a known cure and there has been various lapses in the management therapy. Hence this study was aimed at evaluating the impact of caffeine at the A2A receptors of olfactory bulb, brainstem and striatum of rotenone rat model of Parkinson disease.
 About 55 male Adult Wistar Rats were used for this study. The rats were randomly divided into five groups of 10 rats each with the exception of group B having 15 rats (10 rats for motor PD and 5 rats for premotor PD): Grp A (vehicle; feed + ethanol), Grp B (rotenone 3mg/kg, i.p), Grp C (caffeine 30mg/kg, i.p + rotenone 3mg/kg, i.p), Grp D (rotenone 3mg/kg, i.p + caffeine 30mg/kg, i.p), Grp E (caffeine 30mg/kg, i.p). The animals were subjected to various neurobehavioral protocols, the brains were excised, weighed, appropriate sections taken and processed histologically. The photomicrographs, Morphometric and Statistical analysis were done using Omax led digital Microscope, Image J Software and Graph Pad Prism (7) respectively.
 The results showed a significant decrease in body weight (P<0.05), M/T cells count, neuronal fibres count, increase in level of anxiety (P<0.001), motor deficit, olfactory dysfunction, distortion and degeneration in histopathological presentations in rotenone treated groups, all of these were abrogated/reverse with caffeine treatment. This study was able to establish the therapeutic candidature of caffeine acting as the A2A receptor antagonist to ameliorate the various pathological lesions caused by rotenone administration.
 Keywords: Parkinson disease, Rotenone, Caffeine, A2A receptors, Brainstem, Olfactory Bulb.